It is what as known as a wireless mesh network.
Every aircraft becomes a node in said network.
Satellite, mesh network, whatever nonsense people wish to dream up, the answer is the same.....
Given the limited number of scenarios in which it would be useful, and the rarity of the scenarios, how on earth do you think the manufacturers are going to convince the airlines to (a) pay for the equipment and its installation it across entire fleets (b) Continue paying operational costs to keep the equipment running just incase some rare event occurs given that there are already other mechanisms in place to monitor aircraft.
Its simple, you have to draw a line in the sand somewhere. The methods in use today to monitor aircraft are perfectly good for 99.9999999999% of however many flights that take place every year on this planet !
Do you really think there is any point expending an inordinate amount of man-power and significant money for the 0.0000000001% that may or may not encounter an issue ?
I mean seriously, compared to the number of flights globally ever the same period how many untrackable instances have we had over the last 10 years ? 20 years ?
And then there's the obvious questions about electrical faults, mid-air breakups etc. putting a great big spanner in these dreams people are coming up with....
There may well be other areas of aviation safety where money and man-power would be well spent ..... but this aint' one of them !